The National Park Service has announced a plan to import wolves to Isle Royale National Park, a move designed to restore the natural balance between predator and prey. And that means the island's moose had better watch out.

The park sits in Lake Superior, off the northeastern tip of Minnesota. And for years, wolves and moose have co-existed there. But in recent years, the wolf population has plummeted -- scientists estimate there are only two left. That has led to an increase in the moose population, and has sparked concerns that they will damage the island's vegetation.

Scientists associated with that survey said that without wolf predation, the number of moose could double over the next four or five years. And that would lead to the largest number of moose seen in the study's six decades.

National Park Service Midwest Regional Director Cam Sholly said the recent decision to bring more wolves to the island “is an important step forward in attempting to obtain a proper predator-prey dynamic within the Isle Royale National Park ecosystem.”

Over a three- to five-year period, the agency plans to bring 20 to 30 wolves to the island. It's now working on a detailed plan, including the logistics for capturing, relocating and introducing wolves from the Great Lakes region.